I have a similar issue to several posts here, my dash lights no longer work. I replaced all the lights, I've replaced the fuse, I've replaced the light switch (twice) and have now done the voltmeter bench test on both switches (they both test OK). I have completely rebuilt my dash and insured everything is grounded properly (although, I could be wrong here). All the other lighting is working properly. The turn indicator (and their associated dash light) work. The courtesy door lights, brakes lights, and headlights all work. The issues seems to be only with stuff connected to that gray wire.

On an earlier post, someone suggested I check the back of the fuse panel. I'm a little worried that if I pull the fuse panel I will cause more issues.

Has anyone tried adding LED lights around the gauge bezels? Since my car is a RestoMod I'm thinking this might my next attempt at dash lighting.

 

The dash lights do not run off of the 'Grey' wire. They are connected to the headlight switch via the big round plug on the back of the circuit board. Try checking that the pins on the board are all still solidly attatched to the board. I would suspect that you have a loose pin or two that need to be resoldered, or possibly reseating the plug may get them going. .

 

Also check to see if you have power on both sides of the small 4A INST LPS fuse with the headlight switch on and the rotary **** on it turned to the left almost to where the courtesy lights come on.

 

I put LED's in my 67 and their great, very bright, so bright you can see them in the day time. However then car is in another garage 20 miles from here until a get a garage built here, so i cant tell you what number the are. How about your circuit board on the back of the instruments, i put a new repo one on my and it works fine. As i recall there should be a ground wire coming right off the back of the IP. These pics are taken in the day time.
So this is the first time i have tried to upload pics from my Iphone 8, their rotated and i dont know how to make them straight.

 

I have LEDs in place now but can not get them to light. I was thinking about using a strip of LEDs around the two gauge clusters and power them from a new circuit. I was wondering if anyone has tried something odd like this.

 

Steverw, I know this is an old thread, but is your instrument panel rebuilt? Your gauges look immaculate. Is that the original Rally Pac?

 

I used the sylvania led replacements for 194 / 168 in my 1971. Put the bulbs into the original sockets and some new sockets from Amazon. I found that the led replacements are polarity sensitive. If they don’t work, try turning them around in the socket.